GeForce GTX 690 is a dual-GPU graphics card solution of two GeForce GTX 680 (not SLI) and part of the 600 Series released by NVIDIA in 2012. As usual and a hindrance of dual-GPU graphics cards, the clock frequencies had to be reduced. However, NVIDIA managed to almost double-cross this problem by developing Turbo Boost technology that sets the GPU's core clock from 915 to 1019MHz. The other specs, such as the number of cores, memory speed, and memory bandwidth per GPU are the same on both cards. The Performance is mind-blowing and indicated for gamers that use demanding technologies, such as Tesselation, paired with extreme resolutions and on games already Very Demanding from the start, such as Metro 2033 and The Witcher 2. GeForce GTX 690 is less expensive and energy consuming than GTX 680 put in Dual SLI.

I bought it used 4 month ago for 120€ (138 USD / 106£) and it's still kicking ass but some games (like Nier Automata without FAR) use 2Go+ of VRAM and show that it's a bit old. But when the game is SLI friendly, it's awesome ; )

I mean the 1060 is slightly better, but if cost is a factor I've seen 690s cheaper. Non reference factory overclocked versions of the 780 ti are better in performance for less money, bringing you closer to the mark on a tighter budget

Plus consider SLI as a factor, since getting a second card of a type you already have can be a cheap upgrade as the parts get old. The 1060 has no SLI, the 690 you can run 2 because its already a dual gpu card, but 4x 780s is on the table